1. Field of the Invention
The present invention relates to a display panel and a display device. More specifically, the present invention relates to a display panel and a display device, preferably used in a flat panel display such as an in-car instrumental panel, a car navigation system, a display device for amusement equipment.
2. Description of the Related Art
Flat panel displays (hereinafter, also referred to as a “FPD”) which can be reduced in thickness or increased in size have been widely spread as a display device such as a TV and a display for personal computers. A liquid crystal display device, a plasma display device and the like may be mentioned as a FPD which has been practically used, currently.
According to a common liquid crystal display device, alignment of liquid crystals interposed between a pair of substrates is electrically controlled, and thereby an amount of light passing through the substrates from a backlight is adjusted (dimmed). In such a manner, the common liquid crystal display device displays an image. Such a liquid crystal display device is a slim profile and low-power display device. Further, such a liquid crystal display device has an advantage in that it can be applied to a display device having a screen in a variety of sizes from a small to medium size (42-inch model or so). Accordingly, the liquid crystal display device has been widely used in various applications such as a TV, a display for personal computers, a display for PDAs, a display for amusement equipment.
The plasma display device adopts the same light-emitting principle as in a fluorescent lamp. That is, according to a normal plasma display device, noble gas such as helium and neon is enclosed between the substrates on which electrodes are formed. A voltage is applied to the electrodes, and then the noble gas is converted into a plasma state. And when the gas in a plasma state (ion and electron) is recombined, UV ray is generated and a fluorescent substance formed on the substrate is irradiated with the UV ray. Such a PDP has characteristics such as a fast response speed, a high contrast ratio, a wide viewing angle, and easy upsizing, and it has been widely used as a large-sized TV.
An organic electroluminescent display device (hereinafter, also referred to as an “organic EL display device”) and a field emission display device and the like may be mentioned as a FPD which has been actively researched and developed in order to be more widely used.
According to a common organic EL display deice, a light-emitting layer including an organic light-emitting material is formed between electrodes formed on substrates and a direct-current voltage is applied to this light-emitting layer. In such a manner, the common organic EL display device displays an image. Characteristically, such an organic EL display device can easily attain the following advantages: a reduction in power consumption, a reduction in film thickness, and colorization, and it has been expected to be applied to a display for PDAs.
The field emission display device adopts the same light-emitting principle as in a cathode-ray tube. That is, in a common field emission display device, a space between substrates on which electrodes are formed is maintained in a vacuum, and an electron is emitted from the electrodes toward a fluorescent substance arranged on the substrate, and thereby light is emitted. Characteristically, such a field emission display device can be reduced in thickness or increased in size, and has a power consumption lower than that in a cathode-ray tube. Such a field emission display device has been expected as a next-generation large-sized TV.
Thus, the FPDs have various advantages depending on the kind, but they have almost the same shape (appearance). That is, the FPD generally has substantially rectangular display region and frame. For example, a publicly known liquid crystal display panel has a substantially rectangular planar shape, as shown in FIG. 10A. As shown in FIG. 10B, in a display region 109, pixels 110 are regularly arranged in a matrix pattern. The display region 109 also has a substantially rectangular contour. The liquid crystal display panel generally includes a thin film transistor array substrate 601, a color filter substrate 602, a sealing member 604 for sealing liquid crystals between the thin film transistor array substrate 601 and the color filter substrate 602, and a black mask 605.
For display devices used in applications such as an in-car instrumental panel, a display device for amusement equipment, and the like, diversification of a planar shape of a display region has been increasingly demanded recently, in view of improvement in design properties.
Under the above-mentioned circumstances, a method for producing a liquid crystal display panel having a variety of planar shapes such as an elliptical shape is disclosed (for example, refer to Japanese Kokai Publication No. 2000-75257 and Japanese Kokai Publication No. 2005-195788). Japanese Kokai Publication No. 2000-75257 discloses a technology of preparing a liquid crystal display panel having a desire planar shape using a panel substrate having a desired planar shape which is formed by selectively decomposing and removing a portion of the substrate.
Further, Japanese Kokai Publication No. 2005-195788 discloses a liquid crystal display panel having a circular arc outer shape, which includes a notched portion, and at both of the notched portion and the circular arc outer periphery of the panel, terminals for inputting a driving signal are arranged.
However, these documents hardly disclose a shape, an embodiment, and the like of components in the display region. Further, if pixels are arranged to correspond to the shape of the display panel disclosed in these documents, the pixels need to have a unique shape such as a sector shape and a trapezoid shape. Further, in the display region, the size of the pixels must be appropriately changed. Therefore, it becomes difficult to display an image with uniform display quality in the display region.